I imagine the same thing would happen as it would if I tell the electricity company I didn't use my kettle that day. They'd say they didn't have that level of information and tell me how accurate their meter (or whatever the phone equivalent) is. If they had that sort of info then they wouldn't have had to upgrade the exchanges in order to provide itemised billing would they?
Nothing in the March stuff shows that local calls could be 'read', it doesn't even show any details of local calls - explain? 
Of course it does - it shows that individual calls could be broken down to a particular time of day or night, and how long each call (individually) lasted. The evidence could not be any clearer. All calls could be broken down into individual elements, showing the time of day or night a particular call was made (Cheap rate, Peak rate and Standard rate, charges applied), which was available to the engineers and to the police or the security serveices long befire 1986 - youi cannot hang on the fact that officially itmeised billing was not in the public domain until long after Augfust 1985, to suggest that it was not possible to obtain such information about individual calls, if the engineers could produce that information by other means for the police if requested to do so...
The detail contained in metered call logs provided sufficient information for the police or any of the security services to work with to check whether calls were made or not from a particular telephone line, under the metered call log facility. It is nothing but a smoke screen to suggest that because itemised phone bills did not officially come on line until 1986, that there was no way prior to this that any information was available to the engineers and technicians to be able to do the very same thing using the metered call log system? The other thing to remember is that before the itemised billing came on stream in 1986, it must have been possible for the engineers to produce corresponding information from the metered call logs, so that a program could be implemented to produce the itemized billing which came later?